如何在 DirectX 10 中将后台缓冲区保存到文件？

Question

我想使用 DirectX 10 逐帧渲染视频。这些帧稍后将由 mencoder 或 ffmpeg 等其他工具进行处理。

我在 DX9 中使用 D3DXSaveSurfaceToFile 这样做没有任何问题。

现在，在 DX10 中，我找到了 D3DX10SaveTextureToFile，但没能用它来保存我的后台缓冲区。

我使用以下代码：

ID3D10Resource *backbufferRes;
_defaultRenderTargetView->GetResource(&backbufferRes);

D3D10_TEXTURE2D_DESC texDesc;
texDesc.ArraySize = 1;
texDesc.BindFlags = 0;
texDesc.CPUAccessFlags = D3D10_CPU_ACCESS_READ;
texDesc.Format = backbufferSurfDesc.Format;
texDesc.Height = backbufferSurfDesc.Height;
texDesc.Width = backbufferSurfDesc.Width;
texDesc.MipLevels = 1;
texDesc.MiscFlags = 0;
texDesc.SampleDesc = backbufferSurfDesc.SampleDesc;
texDesc.Usage = D3D10_USAGE_STAGING;

ID3D10Texture2D *texture;
HRESULT hr;
V( _device->CreateTexture2D(&texDesc, 0, &texture) );
_device->CopyResource(texture, backbufferRes);

V( D3DX10SaveTextureToFile(texture, D3DX10_IFF_DDS, filename) );
texture->Release();

这将创建一个 .dds 图像，该图像无法由我所知道的任何类型的 DDS 视图/编辑器打开。

我的代码有什么问题吗？

Answer 1

所有功劳都归功于 gamedev.net 的 sepul。

现在，问题是：

• texDesc.CPUAccessFlags 应该是 0
• texDesc.Format 应该是 DXGI_FORMAT_R8G8B8A8_UNORM
• texDesc.SampleDesc.Count应该是 1
• texDesc.SampleDesc.Quality 应该是 0
• texDesc.Usage 应该是 D3D10_USAGE_DEFAULT

这样 D3DX10SaveTextureToFile 将保存BMP 甚至 PNG。

完整的代码是：

HRESULT hr;
ID3D10Resource *backbufferRes;
_defaultRenderTargetView->GetResource(&backbufferRes);

D3D10_TEXTURE2D_DESC texDesc;
texDesc.ArraySize = 1;
texDesc.BindFlags = 0;
texDesc.CPUAccessFlags = 0;
texDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
texDesc.Width = 640;  // must be same as backbuffer
texDesc.Height = 480; // must be same as backbuffer
texDesc.MipLevels = 1;
texDesc.MiscFlags = 0;
texDesc.SampleDesc.Count = 1;
texDesc.SampleDesc.Quality = 0;
texDesc.Usage = D3D10_USAGE_DEFAULT;

ID3D10Texture2D *texture;
V( _device->CreateTexture2D(&texDesc, 0, &texture) );
_device->CopyResource(texture, backbufferRes);

V( D3DX10SaveTextureToFile(texture, D3DX10_IFF_PNG, L"test.png") );
texture->Release();
backbufferRes->Release();